Drawing compound



Patented Oct. 15, 1929 GEORGE WHITFIELD RICHARDS, OF WAYNE, PENNSYLVANIA DRAWING COMPOUND No Drawing.

My invention relates to an emulsion for the lubrication of metals which are to be drawn, and also to the concentrated base from which the emulsion is prepared.

One object of my invention is to provide a drawing compound in the form of an emulsion which will lubricate the metal to be drawn in a more satisfactory manner than has heretofore been possible, and which at the same time is easy to apply and economical to use.

Another object is to provide a drawing compound of such a nature that the metal piece, after immersion, will be clean in appearance and will have upon its surface a jellylike film of the lubricant adhering thereto, which film will remain in an unchanged condition upon the piece regardless of the length of time between the lubrication and the drawing.

A further object is to provide a metal drawing lubricating bath in the form of a water emulsion which is stable, having no tendency either to deteriorate or become rancid, and which will not become vermin infested even though it is allowed to remain in open trou hs.

Still another object is to provide a base in concentrated form which may be easily transported and which may be emulsified in the mill with the necessary amount of water for the particular work encountered.

Other objects will be apparent from a consideration of the specification and claims.

Heretofore, various attempts have been made to provide lubricants for treating metal before the drawing operation. The metal to be drawn has been smeared with grease or oil throughout its length by hand, which results in wide variations in the amount of lubricant on the individual ieces. The operation is disagreeable and dlflicult to perform as well as costly from a labor standpoint, particularly after the first drawing operation, since then the interior as well as the exterior of the tube must be smeared by hand. Furthermore, since the billets are usually wet, they must be thoroughly dried prior to the smearing. This drying involves labor and furnace costs, as well as additional equipment and loss of time. If it is attempted to smear wet billets with.

Application filed September 27, 1928. Serial 1W. 808,834.

grease or oil, a satisfactory lubrication is not possible due to the grease repelling nature of the water.

Lubrication by means of a bath of flour, tallow and water has also been attempted, but this expenslve mixture does not lubricate properly, particularly after the first immersion. It is not possible to secure a complete emulsification of tallow by means of flour in an open bath and consequentl the tallow floats on the surface and the rst loads of tubes dipped rob the emulsion of a large part of the tallow, thus impoverishing the bath unduly for subsequentv work. The bath is also of short life, since it deteriorates rapidly, becoming rancid. Great trouble is also encountered due to the fact that it soon becomes vermin infested. It is also deleterious to the workmens health, in fact the cause of boils has been traced to its use.

My invention contemplates a drawing compound which, when applied to the metal, is in the form of a water emulsion of a harmless, stable nature, having no tendency to become rancid or vermin infested. The metal billet or tube, after immersion, retains suflicient lubricant on its surface, in the form of a thin jellylike film, to insure a most satisfactory lubrication of both the die and the mandrel of the draw-bench. This film is of a permanent 80 character, and will remain upon the piece unchanged, regardless of the length of time that elapses between the immersion and the drawing. This film also prevents the formation of rust and keeps the piece in a clean, bright condition. The immersion in the water emulsion insures a uniform coating, and when the piece is in the form of a tube, the coating is uniform on the interior as well as the exterior surface. There is no necessity for drying the billets prior to immersion, and the operation may be carried out on a load of tubes at one time by means of a crane, thus reducing the labor costs materially.

The invention also contemplates a concentrated base from which the emulsified metal drawing bath is prepared. The base is ready for use by the mill without treatment other than the addition of the desired amount of water to it. For different types of work, and 00 also for different metals, the concentration will vary, and, therefore, one product can be bou ht by the mill, and the individual baths made up in the concentrationsnecessary.

The concentrated base comprises saponification products including soap, free fat, highly refined cylinder (mineral) oil, and moisture, and is characterized by its ability to form a film or coating of lubricant upon the piece after. removal from the bath, the coating comprising a soap film WhlCh is 1mpregnated by the fat and oil and which binds the fat and oil on the piece. Various soda soaps, fat and mineral oils ma be used to form this film on the piece. T e soda soap may be of any organic radical, provided that the fat from which it is made is at least forty titre, that is to say, the solidifying point of the characteristic fatty acidsderlved from the fat is at least 40 centigrade. The percentage of saponification products including soap in the mixture is approximately twenty parts to thirty parts. T e free fat may be tallow, wool fat, or palm fat. The last named fat is preferred, since 'it has a relatively high degree of acidity which produces cleaner and brighter tubes than other fats lower in acidity. The mineral oil is of a parafiine base and is designated as a highly refined cylinder oil, and various grades may be used, provided the viscosity is relatively high, the lowest limit being approximately 200 seconds Saybolt at 100 Fahrenheit. An oil of the following physical properties has proved satisfactory:

Viscosity at 100 degrees Fahrenheit,

200 seconds Saybolt. Flash point 425 degrees Fahrenheit. Fire point 500 degrees Fahrenheit. Gravity 26 Baum.

The amount of free fat and mineral-oil may vary, but preferably there should be resent about ten parts of each, and generally,t e total of the free fat and mineral Oll equals thirty per cent to fifty per cent of the weight of the base.

I process is usually completed in thirty to sixty minutes. Following the formation of the V soap, the free fat and mineral oil are added gradually and crutched into the soap by the stirring mechanism. The mineral oil is usually but not necessarily added first and the free fat last. During the mixing. of the ingredients, care must be taken to avoid chilling the contents of the kettle unduly in order to insure thorough incorporation and emulsification of the ingredients and a uniform composition throughout. When uniformity of the product is obtained, the steam is shut off, and the contents allowed .to cool and set up preparatory to shipment.

In a typical case, thirty parts of saponification products including soda soap, made from fat of 42.5 titre, twenty parts of palm fat, and twenty parts of triple filtered, cold settled cylinder stock as free from wax as possible with the following properties:

Viscosity Saybolt at 210 degrees Fahrenheit,

145 seconds.

Flash point 550 degrees Fahrenheit. Fire point 625 degrees Fahrenheit. Gravlty 27 degrees Baum.

mixing and to render the material in suitable condition for shipment.

As hereinbefore pointed out, the amount of water added to prepare the emulsified bath for lubrication varies with the metal to be treated and the like. The heavier emulsions are usually used with steel; for example, one part of water added to one part of base, is satisfactory. Generally, however, the dilution is greater, and the average dilution is one part of base to three parts of water. \Vith copper and brass, lighter emulsions are preferred and may vary from one part of base to three parts of Water, to one part of base to twenty or thirty parts of water. The emulsion is usually prepared by passing live steam into a mixing tank containing the concentrated base and a little water. The heat of the steam quickly breaks down the paste to form a heavy emulsion. This emulsion is then transferred to the dip trough whe e additional water is added to reduce the emulsion to the predetermined working strength. This dip trough is usually equippedwith a closed steam coil to keep the emulsion at the temperature desired.

The metal is first freed from scale in pickling acid and then washed in water to remove the traces of the adhering acid and the loose scale. It is then transferred to the trough of emulsion which is preferably at a temperature between one hundred degrees Fahrenheit and one hundred and fifty degrees Fahrenheit, and totally immersed. Care must be taken that there are no air pockets on the interior of the tubes to interfere with the deposit of the thin film of lubricant. In order to insure complete coating, the tubes may be removed, drained and re-immersed two or three times. When they are withdrawn finally, they are allowed to drain, and as the metal cools the lubricant adheres to the surface and sets up to a film which is suflicient to lubricate both the die and mandrel of the draw-bench. In steel mills, the metal is usually annealed after each draw, and the same pickling, washing, lubricating and drawing processes are repeated until the tube of the desired size is obtained.

It may be desirable to leave the tube in the bath until the operator is ready to pass it through the die; in this work, as in the previous case, the emulsion is preferably warm, but as before, if desired, the metal may be treated with the cold emulsion.

The presence of the film of lubricant which, as hereinbefore discussed, encases the entire surface of the piece, probably accounts, at least in part, for the success of the treatment described. While the soap has considerable lubricating value, the lubrication is probably due, for the most part, to the free fat and mineral oil. The soap made from the high titre fat forms the heavy film or soap jell which remains on the piece. The free fat and oil are carried by the film and bound to the piece by it, the soap film being impregnated by the fat and oil.

Considerable modification is possible in the proportion of ingredients used in the preparation of the base, and in the method of compounding it, as well as in the proportion of water added to the base to form the emulsified lubricating bath, without departing from the essential features of the invention.

I claim:

1. A concentrated base adapted for use after emulsification with water as a drawing compound, comprising a homogeneous mixture of twenty parts to thirty parts of soda soap made from a fat of at least forty titre, free fat, and refined cylinder mineral oil whose viscosity is at least two hundred seconds Saybolt at one hundred degrees Fahrenheit, the free fat and the cylinder oil both being present in amounts greater than ten parts and the total of free fat and mineral oil being between 30% and 50% of the total weight of the mixture.

2. A concentrated base adapted for use after emulsification with water as a drawing compound, comprisin a homegeneous mixture of 20% to 30% o soda soap made from a fat of at least forty titre, free fat and refined cylinder mineral oil whose viscosity is at least two hundred seconds Saybolt at one hundred degrees Fahrenheit, the free fat and the cylinder oil both being present in amounts greater than 10% and the total of free fat and the refined cylinder mineral oil being between 30% and 50% of the total weight of the mixture and the balance of the mixture made up of moisture.

3. A concentrated base adapted for use after emulsification with a water as a drawing compound, comprising a homogeneous mixture of approximately thirty parts of soda soap made from a fat of at least forty titre, palm fat approximately twenty parts, and refined cylinder mineral oil whose viscosity is at least two hundred seconds Saybolt at one hundred degrees Fahrenheit twenty parts.

4. A concentrated base adapted for use after emulsification with water as a drawing compound, comprising a homogeneous mixture of approximately 30% of soda soap made from a fat of at least forty titre, palm fat approximately 20%, and refined cylinder mineral oil whose viscosity is at least two hundred seconds Saybolt at one hundred degrees Fahrenheit 20%, and the balance of the mixture made up of moisture.

5. An emulsified metal drawing bath comprising an emulsion made up of water in an amount equal to at least 50% and a concentrated base, the concentrated base having therein from twenty parts to thirty parts of soda soap made from a fat of at least forty tit-re, free fat and refined cylinder mineral oil whose viscosity is at least two hundred seconds Saybolt at one hundred degrees Fahrenheit, the free fat and the cylinder oil both being present in amounts greater than ten parts and the total of free fat and mineral oil being between 30% and 50% of the total weight of the concentrated base.

6. An emulsified metal drawing bath comprising an emulsion made up of water in an amount equal at least to 50% and a concentrated base, the concentrated base having therein approximately thirty parts of soda made from a fat of at least forty titre, palm fat approximately twenty parts, and a refined cylinder mineral oil whose viscosity is at least two hundred seconds Saybolt at one hundred degrees Fahrenheit twenty parts. G. WHITFIELD RICHARDS. 

